Bava Basra 84a ~ What Color is the Sun?

We are studying the tractate Bava Basrsa (The Last Gate), which is currently dealing with the circumstances under which the sale of goods may be voided.  The Mishnah (83b) ruled that if there is agreement to sell red wheat (שחמתית) and it was found to be white (לבנה), both the seller and the buyer have legal grounds to retract. The Talmud then discusses the names for these colors: what we call red and white are called "like the sun" and "like the moon." Rav Pappa (the Babylonian sage who died in 375CE) took this a step further:

בבא בתרא פד, א

שחמתית ונמצאת לבנה כו': אמר רב פפא מדקתני לבנה ש"מ האי שמשא סומקתי היא תדע  דקא סמקא צפרא ופניא והאי דלא קא חזינן כוליה יומא נהורין הוא דלא ברי

Rav Pappa said: From the fact that the Mishnah refers to one type of wheat as white, we should conclude from this that the sun is red, not white. We know that this is the case, because the sun is red in the morning and in the evening. The reason that we do not see the red color all day is because our eyesight is not strong and we cannot discern the redness of the sun.

Shmuel ben Meir, known as Rashbam (d. ~1158) explained that "our eyes are not able to discern the colors very well because in the middle of the day the light is blinding. But in the morning and the evening, when the sun is less bright, we can see the redness of the sun."

 מאור עינינו אינו ברור כל כך מתוך אור היום שמכהה עינינו אבל צפרא ופניא שהיום חשוך ניכר אדמומית החמה ורב פפא לפרש משנתנו בא אמאי מקרי שחמתית

According to Rav Pappa, the true color of the sun is red - but this true color can be seen only when the sun is at its least intense - in the evening and the morning. We have all experienced Rav Pappa's description: who cannot be moved by the sight of a blazing red sunrise or sunset? But what is the scientific explanation of these colors?

The Color of the Sun in Space, and on Earth

According to NASA experts (who really are rocket scientists, among other things), the sun emits all colors of the visible light spectrum. And when you mix all these colors together you get...white. If you were to look at the sun from high in space, (perhaps aboard the International Space Station), it would indeed appear to be a pure white.  Like this:

Courtesy of NASA.

Courtesy of NASA.

It was in the seventeenth century that Isaac Newton used a prism to split the sun's light into its constituent colors. Before then it was raindrops that did the same thing, forming a rainbow as a result.

Isaac Newton divided  a ray of sunlight with a prism in a series of experiements published in 1672.  Lego recreation is from here.

Isaac Newton divided  a ray of sunlight with a prism in a series of experiements published in 1672.  Lego recreation is from here.

The white light of the sun changes as it passes through our atmosphere, which absorbs and scatters much of the shorter wavelength blue light. (That is why the sky is blue, whatever else your dad may have told you.) However the longer wavelength red light is not absorbed, and passes pretty much unchanged.  So we see the sun as more red than blue.  This effect is especially apparent at sunrise and sunset, when in order to reach our eyes, the sunlight has to pass through more of our atmosphere. More of the shorter wavelength blue light is then absorbed, leaving even more of that longer wavelength red light. And as a result, we see those glorious red sunsets (and for those who can get up early enough, red sunrises too).

Here on Earth, the atmosphere plays a role in the color of the sun. Since shorter wavelength blue light is scattered more efficiently than longer wavelength red light, we lose some of the blue tint of the sun as sunlight passes through the atmosphere. In addition, all wavelengths of visible light passing through our atmosphere are attenuated so that the light that reaches our eyes does not immediately saturate the cone receptors. This allows the brain to perceive color from the image with a little less blue – yellow.


The Cultural determinants of the Sun's Color

On their website, the NASA scientists claim that "sometimes the display color of the Sun is culturally determined. If a kindergartener in the USA colors a picture of the Sun, they will usually make it yellow. However, a kindergartener in Japan would normally color it red!"  The rabbis of the Talmud had their own cultural explanation of the colors of the sun.  After later suggesting that the color of the sun may actually be white (because that is the color of a patch of skin with zora'at, usually identified as a kind of leprosy), the Talmud then explains the cause of the red sunrises and sunsets:  

ולמאי דסליק דעתין מעיקרא הא קא סמקא צפרא ופניא בצפרא דחלפא אבי וורדי דגן עדן בפניא דחלפא אפתחא דגיהנם

In the morning it becomes red as it passes over the site of the roses of the Garden of Eden, whose reflections give the light a red hue. In the evening the sun turns red because it passes over the entrance of Gehenna, whose fires redden the light...

Without the scientific understanding we have today, the Talmud claimed that the red color of sunrise and sunset was due to the light filtering though the red roses of the Garden of Eden, and fires of Hell.

is the Garden of Eden real or metaphorical?

It would seem that the Talmud's description of the locations of the Garden of Eden and the Gates of Hell is to be taken literally, for it is given as an explanation for physical phenomena.  But here is where things can get tricky. The famous rabbi Joseph Hayyim of Baghdad (1834–1909) wrote a work that is widely read by Sephardic Jews to this day called Ben Ish Hai. He also  published three volumes of responsa between 1901 and 1905 called Rav Pe’alim. (A fourth volume was posthumously published in 1912.) In an undated question, R. Hayyim was asked about the location of the Garden of Eden. In one tradition, the garden was located “on the other side of the world,” somewhere below the equator in the southern hemisphere. However, the questioner continued, the world has been circumnavigated, and the Garden of Eden has not been identified. Where then is it located?

In his answer, R. Hayyim digressed into the truth claims of science, and then returned to the location of the Garden of Eden. He noted that although it may be located on the Earth itself, it existed on a different spiritual plane and would therefore not be perceived by the human senses. I suppose many moderns would agree with the suggestion that the Garden of Eden is not to be found in a geographic location. But today's page of Talmud reminds us that at least in talmudic Babylon, the Garden of Eden was not just a metaphor.  It determined the very colors of the sun.